1 // SPDX-License-Identifier: GPL-2.0
2 #include <linux/bpf.h>
3 #include <bpf/bpf_helpers.h>
4 #include "bpf_legacy.h"
5
6 struct {
7 __uint(type, BPF_MAP_TYPE_PROG_ARRAY);
8 __uint(max_entries, 2);
9 __uint(key_size, sizeof(__u32));
10 __uint(value_size, sizeof(__u32));
11 } jmp_table SEC(".maps");
12
13 __noinline
subprog_tail2(struct __sk_buff * skb)14 int subprog_tail2(struct __sk_buff *skb)
15 {
16 volatile char arr[64] = {};
17
18 if (load_word(skb, 0) || load_half(skb, 0))
19 bpf_tail_call_static(skb, &jmp_table, 10);
20 else
21 bpf_tail_call_static(skb, &jmp_table, 1);
22
23 return skb->len;
24 }
25
26 static __noinline
subprog_tail(struct __sk_buff * skb)27 int subprog_tail(struct __sk_buff *skb)
28 {
29 volatile char arr[64] = {};
30
31 bpf_tail_call_static(skb, &jmp_table, 0);
32
33 return skb->len * 2;
34 }
35
36 SEC("tc")
classifier_0(struct __sk_buff * skb)37 int classifier_0(struct __sk_buff *skb)
38 {
39 volatile char arr[128] = {};
40
41 return subprog_tail2(skb);
42 }
43
44 SEC("tc")
classifier_1(struct __sk_buff * skb)45 int classifier_1(struct __sk_buff *skb)
46 {
47 volatile char arr[128] = {};
48
49 return skb->len * 3;
50 }
51
52 SEC("tc")
entry(struct __sk_buff * skb)53 int entry(struct __sk_buff *skb)
54 {
55 volatile char arr[128] = {};
56
57 return subprog_tail(skb);
58 }
59
60 char __license[] SEC("license") = "GPL";
61